Sectional parabolic antenna system



De@ 31, 1946 DE wlTT R. GODDARD SECTIONAL PARABOLIC ANTENNA SYSTEM 2 sheeisfsheet 1 Filed June 24, '1943 Dec. 31, 1946. DE WITT R. GoDDARD SECTIONAL PARABOLIC ANTENNA SYSTEM Filed June 24, 1945 2 Sheets-Sheet 2 'eW by '7 ArroPA/EV Patented Dec. 31, 1946 sEcfrIoNAL PARABOLIC ANTENNA SYSTEM De Witt Rugg Goddard, Riverhead, N. Y., assignor to Radio Corporation of America, a corporation of Delaware Application June 24, 1943, Serial No. 492,032

9 Claims.

This invention relates to a new and useful split lParabolic antenna system for use with an ultra high frequency radio transceiver.

An object of this invention is to provide an efficient light weight compact portable parabolic antenna for use in ultra high frequency systems for two-way voice communication. My invention is particularly useful for short waves of the order of ten centimeters in length.

Another object of this invention is to provide a portable waterproof three-piece parabolic an- .tenna in which each separate portion is insulated from the other.

My invention employs a novel construction wherein a parabolic reflector is split into three pieces, namely, a center section and two side sections. Suitable means for removably fastening the sides on the center section are provided.

A feature of this invention resides in the fact that the center section of the parabolic reflector serves to form a portion of a control box which houses the radio frequency unit and is arranged with another box or cover portion to house the side sections and other devices.

Parabolic reflectors are old in the art, there being many different arrangements. Generally,

they are large in size, and therefore cumbersome and heavy to carry. This invention overcomes these objections since by splitting the reflector into three major component parts, capable of being readily assembled, detached and stored away in a suitable container, portability, without loss of electrical ei'liciency, as will be explained later, is insured.

The parabolic reflector of this invention is par- `ticularly adapted for forming the antenna system of Aa portable two-way voice radio communication system operating at a wavelength of about ten centimeters, although, obviously, the invention is not limited to operation at this frequency. The antenna system described herein is intended to be used with a transceiver similar to -theone described in a copending application of K. MacLean and DeWitt R. Goddard, filed May 20, 1943, Serial No. 487,722. A

This invention will best lbe understood by referring to the accompanying drawings in which: Fig. 1 is a front elevation of the split parabolic reflector of this invention,

Fig. 2 is a cross-section taken on 2-2 of Fig. l, Fig. 3 is a perspective View partly in section showing a portion of one of the side sections;

Fig'. 4' is a perspective 'view of the box portion formed by the center section of the parabolic reflector, and

v Fig. 5 is an end view of Fig. 4.

Referring/now in detail to Figs. 1, 2 and of the drawings, .the center section l is shown mountedfupon a telescoping tripod 2. On each side of the center section there are located side sections or wings 3 and 4 which are arranged to be detached from the center section I by means of a flat arcuate clamp strip 5. The end portions of the side sections are riveted to an angular member 6 which is arranged to slide under the arcuate strip 5. The side sections 3 and 4 are attached and detached by .a thumb screw 1- which engages the slots 8 in the angular portion 6 and passes through the arcuate strip 5. The angular member 6 is provided with a plurality of slots 8 which are shown more in detail in Fig. 3 of the drawings. It will be seen that the thin parabolic reflecting surface 3 has Ithe special aluminum angular portion 6 riveted thereon by means of rivets 6A. This angle material contains a circular perforation 5A located at the top and several half round notches 8 which are distributed along its edge. The main center section or box portion l contains an arcuate strip 5 which is held in position by means of three loose fitting rivets SB and the knurled thumb screw l clamps the side sections 3 and 4 together. At the upper left hand corner of the box portion a stud 5B protrudes about one quarter of an inch beyond the surface of the strip '5. The threaded .brass plate 1A is arranged to receive the .threaded thumb screw 1. The plate 1A is fastened to the sides of the wood box I by lmeans of small screws 1B. The center section tor I0 is in the form of a simple dipole located' at the end of a coaxial transmission line (not shown) 'and isolated therefrom by two quarterwave sections. In front of the dipole 10A and insulated therefrom, is another dipole 10B which is used as .a reflector. The latter is insulated from IBA since it is molded in thermoplastic insulating material such as lucite or polystyrene. The arrangement as a whole is such as to throw the majority of the radiations against the parabolic reflecting surfaces I, 3 and 4 of the reflector. The lower portion of the center section has located therein a threaded ange member Il which is threaded at ,l2 to receive a clamping bolt i3 for securing the center section to the tripod 2. To the right of flange H there is located a connection socket I4 which is arranged to receive ya plug and'cable i5 which connects thef radiator l0 and transceiver to the battery and vibrator power supply box I6 located at the base of the tripod. Connection is made from radiator I0 and transceiver to the socket III by means of leads I'I which are housed in the rear portion within the box transceiver portion of the center section.

As the parabolic antenna reflector unit of this invention is intended for outdoor use, I prefer to cover the entire surface of the antenna radiator IEI and the members I, 3 and il with a low loss insulating material such as Amphenol to avoid detuning effects due to rain, snow or ice forming on the antenna itself. A coaxial line is preferred to feed the antenna which is isolated by two quarter wavelengths arranged in the usual fashion.

Referring to Figs. 4 and 5 of the drawings, there is shown how the cover and box portions of the center section are joined for carrying. The cover portion 2E! serves for enclosing the side sections and also other control devices such as the radiator Iii, head-phones Iii, and plug and cable I5, which devices are located within the connues of the box cover portion when the box is closed. The cover portion ZIB is provided with a carrying handle 2l and is secured to the box or transceiver portion of the center section by means of suitcase clasp members 22 and The lower portion cf center section i contains a radio frequency device in the form of a transceiver which occupies approximately the lower third portion of the box. Its tuning and volume control knobs 2d are located on a panel at the rear of the box. Access to these controls is accomplished by having an aluminum cover plate pivotally secured to the box by means of a Fastened to this cover plate are two inwardly i'oi canvas shields 2i which are arranged so that in the operation of the transceiver the plate i5 and canvas shields 2i in the open position constitute an effective rain shield. In Fig. 2 the cover plate and shield are shown in the closed position with the' open position shown by dash lines. In Fig. 4 the rain shield is indicated in the open position with the control knobs i exposed for operation. To transport the reiiector the canvas shields are folded inwardly, then pressed down and covered by the aluminum plate 25. At the lower portion of plate 25 there are two leather straps 28 which are snapped by means of glove fasteners 2i) to the bcttomof the box l, as shown in Fig. 5.

In the operation and assembly of this system the perforation 5A of the wing or end sections is placed over the stud 5B and then the wing is swung into operating position so that, the angle portion of the wing slides beneath the arcuate strip il until the notches d coincide with the rivets EB and the thumb screw "1. The thumb screw l is then tightened and the wing slid into the position shown inl Figs, 1 and 2 and the entire rel'iector is then complete. The antenna radiator iii is plugged in the metallic connection bushing The thumb screw I3 is tightened to secure the center section I to tripod 2. Electrical connection from the transceiverto the power supply IS is made by means of cable and plug being inserted in socket I4. Theparabolic'antenna system is then ready for use.

It will be noted that no electrical contactV is made between the side sections 3 and l and the center section i. In fact I prefer to deliberately insulate the entire surface of the sideA sections with low loss4 insulating material for the reason that I ind that poor contact generally causes noise in the receiver when electrical contact is made. It is to be understood that the parabolic reflector surface may be cut into other shapes than those shown in Figs. 1 and 2 and dierent arrangements may be made where necessary to provide electrical contact between sections.

While I have indicated and described a preferred system for carrying my invention into effect, many modifications may be made without departing from the scope of my invention.

What I claim is:

l. A parabolic ultra high frequency antenna system comprising a rectilinear box portion having one of its surfaces forming a center section, two side sections insulatingly secured to said box portion so as to be detached from each side of said center section.

2. A high frequency reector comprising a central section, a pair of side sections removably secured thereto, the entire surface of said central section and said side sections being covered with a low loss insulating material to avoid detuning effects due to foreign material coming in contact with said reflector.

3. An ultra high frequency antenna system comprising a parabolic reflector including a rectilinear box portion having one of its surfaces forming a center section and having two side sections insulatingly secured thereto so as to be detached from each side of said center section, said box portion being adapted for enclosing a radio frequency device, a removable cover portion cooperating with said box portion for enclosing said side sections.

4. An ultra high frequency antenna system comprising a parabolic reflector including a rectilinear box portion having one of its surfaces forming a center section and having two side sections secured thereto so as to be detached from each side of said center section, said center section being arranged with straight ends to form a portion of a lbox for enclosing a radio frequency device, the entire surface of said center section and said side sections being covered with a low loss insulating material to avoid detuning effects due toforeign material coming in Contact with said reector, a cover portion cooperating with said center section for enclosing said side sections, and fastening means secured to the lower portion of an end of said center section for fastening the reector to a tripod.

5. An ultra high frequency antenna system comprising a parabolic reflector including a rectilinear box portion having one of its surfaces forming a center section and having two side sections secured thereto so as to be detached from each side of said center section, the entire surface of said center section and said sidesections being ccvered with a low loss insulating material to avoid detuning effects due to foreign material coming in contact with said reector, said center section being arranged with straight ends in the form of a box, a cover portion cooperating with said center section for enclosing said side sections, a radio frequency device lo,- cated in said center section, fastening means secured to the lower portion of an end of said center section for fastening the reflector to a tripodwhich is arranged at one end of said center section, and a socket portion located adjacent said fastening means for the tripod for elec trically connecting said radio frequency device to a source of power.

6. A parabolic, ultra high frequency antenna system comprising a rectilinear box portion hav,.- ing one of its surfaces forming a center section, two side sections secured to said box portion so as to be detached from each side of said center section, the entire surface of said center' section and said side sections being covered with a low loss insulatingmaterial to avoid detuning effects due to foreign material coming in contact with said reflector, an antenna radiator and a radio frequency device located in the central portion of said center section.,

7. A parabolic ultra high frequency antenna system comprising a rectilinear box portion having one of its surfaces forming a center section, two side sections with angular slotted portions arranged to be detached from each side of said box portion, the entire surface of said center sec tion and said side sections being covered with a low loss insulating material to avoid detuning effects due to foreign material coming in contact with said reflector, and mechanical engaging means secured to said box portion of the center section for the engaging angular slotted portions located at the ends of said side sections for fastening them to the center section.

8. An ultra highfrequency antenna system comprising a parabolic reflector including a center section having two side sections secured thereto, the entire surface of said center section and said side sections being covered with a low loss insulating material to avoid detuning effects due to foreign material coming in contact with said reflector, said center section being arranged in the form of a rectilinear box, a transceiver 1ocated within the box portion of said center section, a cover portion cooperating with said center section for enclosing said side sections when it is desired to transport said antenna system, fastening means secured to the lower portion of said center section for fastening the reflector to a l;ripod which is arranged at one end of said center section and a socket portion located adjacent thereto for electrically connecting said transceiver to a source of power.

9. An ultra high frequency antenna system comprising a parabolic reflector including a center section having two side sections secured thereto, said center section being arranged in the form of a rectilinear box, a radio frequency device located in the lower portion of said center vsection, an operating panel maintained at the rear of said center section, a hinged waterproof cover arranged to be folded over said panel, a cover portion cooperating with said center section for enclosing said side sections when it is desired to transport said antenna system, fastening means secured to the lower portion of said center section for fastening the reflector to a tripod which is arranged at one end of said center section and a socket portion located adjacent thereto for electrically connecting said radio frequency device to a source of power.

DE WITT RUGG GODDARD. 

